Group 6 transition metal-containing compounds for vapor deposition of group 6 transition metal-containing films

ABSTRACT

Disclosed are Group 6 film forming compositions comprising Group 6 transition metal-containing precursors selected from the group consisting of:
 
M(═O) 2 (OR) 2   Formula I,
 
M(═O)(NR 2 ) 4   Formula II,
 
M(═O) 2 (NR 2 ) 2   Formula III,
 
M(═NR) 2 (OR) 2   Formula IV, and
 
M(═O)(OR) 4   Formula V,
 
wherein M is Mo or W and each R is independently H, a C1 to C6 alkyl group, or SiR′ 3 , wherein R′ is H or a C1 to C6 alkyl group. Also disclosed are methods of synthesizing and using the disclosed compositions to deposit Group 6 transition metal-containing films on substrates via vapor deposition processes.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a divisional of U.S. patent application Ser.No. 15/503,635 filed Feb. 13, 2017, which is a 371 application ofPCTJP2015/004031 filed Aug. 11, 2015, which claims the benefit of U.S.Provisional Application Ser. No. 62/037,469 filed Aug. 14, 2014, hereinincorporated by reference in its entirety for all purposes.

TECHNICAL FIELD

Disclosed are Group 6 film forming compositions comprising Group 6transition metal-containing precursors. Also disclosed are methods ofsynthesizing and using the disclosed precursors to deposit Group 6transition metal-containing films on substrates via vapor depositionprocesses.

BACKGROUND

Tungsten finds many different applications useful for the fabrication ofnano-devices. Deposition of pure tungsten may be used to fill the holesthat make contact to the transistor source and drain (“contact holes”)and also to fill vias between successive layers of metal. This approachis known as a “tungsten plug” process. The usage of tungsten may bedeveloped due to the good properties of the films deposited using WF₆.However, it is necessary to provide an adhesion/barrier layer, such asTi/TiN, to protect the underlying Si from attack by fluorine and toensure adhesion of tungsten to the silicon dioxide.

Tungsten-silicide may be used on top of polysilicon gates to increaseconductivity of the gate line and thus increase transistor speed. Thisapproach is popular in DRAM fabrication, where the gate is also the wordline for the circuit. WF₆ and SiH₄ may be used, but dichlorosilane(SiCl₂H₂) is more commonly employed as the silicon source, since itallows higher deposition temperatures and thus results in lower fluorineconcentration in the deposited film.

Tungsten nitride (WN_(x)) is considered to be a good barrier againstdiffusion of copper in microelectronics circuits. WN_(x) may also beused in electrodes for thin-film capacitors and field-effect transistor.

Molybdenum oxide may be used as a thin layer for DRAM capacitors. See,e.g., US2012/309162 or US2014/187015 to Elpida. The molybdenum oxidelayer may be deposited on a TiN layer before deposition of a ZrO₂ layer.The molybdenum oxide layer may then help increase the deposition rate ofthe ZrO₂ layer. The molybdenum oxide layer may be deposited on the ZrO₂layer and a TiN layer deposited on the molybdenum oxide layer producinga TiN/MoO_(x)/ZrO₂/MoO_(x)/TiN stack. The molybdenum oxide layers in thestack may reduce leakage current.

Electrochromic devices are optoelectrochemical systems that change theiroptical properties, essentially their transmittance, when a voltage isapplied. As a result, the optoelectrochemical systems may be used inmany applications, such as, but not limited to, smart windows, sunroofs,shades, visors or rear view mirrors, flat panel displays for automotive,architectural, display, and optoelectrical applications like skylights,panel displays, aquariums, light filters and screens for light pipes andother optoelectrical devices. Transition metal oxides have been used asinorganic electrochromic materials. Among those transition metal oxides,tungsten trioxide, WO₃, an n-type semiconductor, is one of the mostextensively studied materials due to its electrochromic properties inthe visible and infrared region, high coloration efficiency, andrelatively low price. The color of WO₃ changes from transparent oryellow to deep blue when it is reduced under cathodic polarization.

Organic Light Emitting Diode (OLED) devices involve emission of light ata specific wavelength range when a voltage is applied. The use oftransition metal oxides as the electrode interface modification layer atanode and cathode in OLEDs has also been reported for reducing theoperational voltage, one of the main parameter to improve devicereliability. Among those transition metal oxides, tungsten oxide ormolybdenum oxide as an anode buffer layer offers advantages such as veryhigh transparent in the visible region and energy level matching withorganic molecules. (Applied Physics Letters, 2007, 91, 113506).

JP07-292079 discloses metathesis catalyst precursors having the formulaM(Y)(OR²)_(x)(R³)_(y)(X)_(z)L_(s), wherein M is Mo or W; Y is ═O or═NR′; R¹, R², and R³ is alkyl, cycloalkyl, cycloalkenyl, polycycloalkyl,polycycloalkenyl, haloalkyl, haloaralkyl, (un)substituted aralkyl, arom.groups containing Si; X=halogen; L=Lewis base; s=0 or 1; x+y+z=4; andy≥1. The catalyst precursor is synthesized from M(Y)(OR²)₄, such asW(═O)(OCH₂tBu)₄.

Chisholm et al. disclose preparation and characterization of oxoalkoxides of molybdenum. Inorganic Chemistry (1984) 23(8) 1021-37.

WO2014/143410 to Kinestral Technologies Inc. discloses multi-layerelectrochromic structures comprising an anodic electrochromic layercomprising lithium, nickel, and a Group 6 metal selected from Mo, W, andcombinations thereof. Abstract. Para 0107 discloses that the source(starting) material for the Group 6 metal may be (RO)₄MO.

David Baxter et al. Chemical Communications (1996), (10), 1129-1130describes the use of different tungsten(VI) oxo alkoxides andtungsten(VI) oxo alkoxide β-diketonate complexes that are volatileprecursors for low-pressure CVD of tungsten oxide electrochromic films.However, the molecules may be solid, difficult to purify effectively, orcostly to prepare due to relatively high number of synthesis steps.

WO99/23865 to Sustainable Technologies Australia Ltd. discloses thatsynthesis of tungsten (VI) oxo-tetra-alkoxide [WO(OR)₄] from WOCl₄,alcohol and ammonia produces an insoluble tungsten-containing compound.WO99/23865 discloses that excess ammonia can be added to dissolve theprecipitated tungsten compound, but that the final tungsten oxideobtained is unsuitable as a film for electrochromic applications.

M. Basato et al. Chemical Vapor Deposition (2001), 7(5), 219-224 alsodescribes the use of W(═O)(OtBu)₄ by self-evaporation, in combinationwith H₂O, to form WO₃ material at 100-150 C.

J. M. Bell et al. describe the preparation of tungsten oxide film forelectrochromic devices using W(═O)(OnBu)₄ (Solar Energy Materials andSolar Cells, 2001, 68, 239).

Dmitry V. Peryshkov and Richard R. Schrock describe the preparation ofW(═O)(OtBu)₄ from W(═O)Cl₄ and Li(OtBu). Organometallics 2012, 31,7278-7286.

Parkin et al. disclose CVD of Functional Coatings on Glass in Chapter 10of Chemical Vapour Deposition: Precursors, Processes and Applications.Section 10.4.3 discloses that several tungsten alkoxides, oxo alkoxides,and aryl oxides have been investigated, such as WO(OR)₄, wherein R=Me,Et, iPr, and Bu. Parkin et al. note that these precursors provide asingle source precursor, with no need for a second oxygen precursor.Parkin et al. note that these precursors suffer from low volatility.

U.S. Pat. No. 7,560,581B2 discloses the use of the bis-alkylimidobis-dialkylamino tungsten precursors for the production of tungstennitride in ALD mode with or without plasma for copper barrier diffusionapplications.

Miikkulainen et al. disclose ALD deposition using Mo(NR)₂(NR′₂)₂precursors. Chem Mater. (2007), 19, 263-269; Chem. Vap. Deposition(2008) 14, 71-77. Chiu et al. disclose CVD deposition of MoN usingMo(NtBu)₂(NHtBu)₂. J. Mat. Res. 9 (7), 1994, 1622-1624.

A need remains for developing novel, liquid or low melting point (<50°C.), highly thermally stable, Group 6 precursor molecules suitable forvapor phase thin film deposition with controlled thickness andcomposition at high temperature.

Notation and Nomenclature

Certain abbreviations, symbols, and terms are used throughout thefollowing description and claims, and include:

As used herein, “Group 6” refers to column 6 of the Periodic Table,containing Cr, Mo, and W.

As used herein, the indefinite article “a” or “an” means one or more.

As used herein, the terms “approximately” or “about” mean±10% of thevalue stated.

As used herein, the term “independently” when used in the context ofdescribing R groups should be understood to denote that the subject Rgroup is not only independently selected relative to other R groupsbearing the same or different subscripts or superscripts, but is alsoindependently selected relative to any additional species of that same Rgroup. For example in the formula MR¹ _(x) (NR²R³)_((4-x)), where x is 2or 3, the two or three R¹ groups may, but need not be identical to eachother or to R² or to R³. Further, it should be understood that unlessspecifically stated otherwise, values of R groups are independent ofeach other when used in different formulas.

As used herein, the term “alkyl group” refers to saturated functionalgroups containing exclusively carbon and hydrogen atoms. Further, theterm “alkyl group” refers to linear, branched, or cyclic alkyl groups.Examples of linear alkyl groups include without limitation, methylgroups, ethyl groups, propyl groups, butyl groups, etc. Examples ofbranched alkyls groups include without limitation, t-butyl. Examples ofcyclic alkyl groups include without limitation, cyclopropyl groups,cyclopentyl groups, cyclohexyl groups, etc.

As used herein, the abbreviation “Me” refers to a methyl group; theabbreviation “Et” refers to an ethyl group; the abbreviation “Pr” refersto a propyl group; the abbreviation “nPr” refers to a “normal” or linearpropyl group; the abbreviation “iPr” refers to an isopropyl group; theabbreviation “Bu” refers to a butyl group; the abbreviation “nBu” refersto a “normal” or linear butyl group; the abbreviation “tBu” refers to atert-butyl group, also known as 1,1-dimethylethyl; the abbreviation“sBu” refers to a sec-butyl group, also known as 1-methylpropyl; theabbreviation “iBu” refers to an iso-butyl group, also known as2-methylpropyl; the abbreviation “amyl” refers to an amyl or pentylgroup; the abbreviation “tAmyl” refers to a tert-amyl group, also knownas 1,1-dimethylpropyl.

The standard abbreviations of the elements from the periodic table ofelements are used herein. It should be understood that elements may bereferred to by these abbreviations (e.g., Mn refers to manganese, Sirefers to silicon, C refers to carbon, etc.).

SUMMARY

Disclosed are Group 6 film forming compositions comprising Group 6transition metal-containing precursors selected from the groupconsisting of:M(═O)(NR₂)₄  Formula I,M(═O)₂(NR₂)₂  Formula II,M(═NR)₂(OR)₂  Formula III,M(═O)(OR)₄  Formula IV, andM(═O)₂(OR)₂  Formula V,wherein M is Mo or W and each R is independently H, a C1 to C6 alkylgroup, or SiR′₃, wherein R′ is H or a C1 to C6 alkyl group. Thedisclosed precursors may include one or more of the following aspects:

-   -   M being Mo;    -   M being W;    -   the precursor having the formula M(═O)(NR₂)₄;    -   each R independently being selected from H, Me, Et, nPr, iPr,        tBu, sBu, iBu, nBu, tAmyl, SiMe₃, SiMe₂H, or SiH₂Me;    -   each R independently being selected from H, Me, Et, iPr, or tBu;    -   the precursor being Mo(═O)(NMe₂)₄;    -   the precursor being Mo(═O)(NMeEt)₄;    -   the precursor being Mo(═O)(NEt₂)₄;    -   the precursor being Mo(═O)(NiPr₂)₄;    -   the precursor being Mo(═O)(NnPr₂)₄;    -   the precursor being Mo(═O)(NiBu₂)₄;    -   the precursor being Mo(═O)(NnBu₂)₄;    -   the precursor being Mo(═O)(NtBu₂)₄;    -   the precursor being Mo(═O)(NsBu₂)₄;    -   the precursor being Mo(═O)(NtAm₂)₄;    -   the precursor being Mo(═O)(NMe₂)₂(NtBu₂)₂;    -   the precursor being Mo(═O)(NiPr₂)₂(NtBu₂)₂;    -   the precursor being Mo(═O)(N(SiMe₃)₂)₄;    -   the precursor being Mo(═O)(N(SiHMe₂)₂)₄;    -   the precursor being Mo(═O)(N(SiMeH₂)₂)₄;    -   the precursor being Mo(═O)(NHMe)₄;    -   the precursor being Mo(═O)(NHEt)₄;    -   the precursor being Mo(═O)(NHiPr)₄;    -   the precursor being Mo(═O)(NHnPr)₄;    -   the precursor being Mo(═O)(NHiBu)₄;    -   the precursor being Mo(═O)(NHnBu)₄;    -   the precursor being Mo(═O)(NHtBu)₄;    -   the precursor being Mo(═O)(NHsBu)₄;    -   the precursor being Mo(═O)(NHtAm)₄;    -   the precursor being Mo(═O)(NHMe)₂(NtBu₂)₂;    -   the precursor being Mo(═O)(NiPr₂)₂(NHtBu)₂;    -   the precursor being Mo(═O)(NHSiMe₃)₄;    -   the precursor being Mo(═O)(NH(SiHMe₂))₄;    -   the precursor being Mo(═O)(NH(SiMeH₂))₄;    -   the precursor being Mo(═O)(NHiPr)₂(N(SiMe₃)₂)₂;    -   the precursor being Mo(═O)(NiPr₂)₂(N(SiMe₃)₂)₂;    -   the precursor being W(═O)(NMe₂)₄;    -   the precursor being W(═O)(NMeEt)₄;    -   the precursor being W(═O)(NEt₂)₄;    -   the precursor being W(═O)(NiPr₂)₄;    -   the precursor being W(═O)(NnPr₂)₄;    -   the precursor being W(═O)(NiBu₂)₄;    -   the precursor being W(═O)(NnBu₂)₄;    -   the precursor being W(═O)(NtBu₂)₄;    -   the precursor being W(═O)(NsBu₂)₄;    -   the precursor being W(═O)(NtAm₂)₄;    -   the precursor being W(═O)(NMe₂)₂(NtBu₂)₂;    -   the precursor being W(═O)(NiPr₂)₂(NtBu₂)₂;    -   the precursor being W(═O)(N(SiMe₃)₂)₄;    -   the precursor being W(═O)(N(SiHMe₂)₂)₄;    -   the precursor being W(═O)(N(SiMeH₂)₂)₄;    -   the precursor being W(═O)(NHMe)₄;    -   the precursor being W(═O)(NHEt)₄;    -   the precursor being W(═O)(NHiPr)₄;    -   the precursor being W(═O)(NHnPr)₄;    -   the precursor being W(═O)(NHiBu)₄;    -   the precursor being W(═O)(NHnBu)₄;    -   the precursor being W(═O)(NHtBu)₄;    -   the precursor being W(═O)(NHsBu)₄;    -   the precursor being W(═O)(NHtAm)₄;    -   the precursor being W(═O)(NHMe)₂(NtBu₂)₂;    -   the precursor being W(═O)(NiPr₂)₂(NHtBu)₂;    -   the precursor being W(═O)(NHSiMe₃)₄;    -   the precursor being W(═O)(NH(SiHMe₂))₄;    -   the precursor being W(═O)(NH(SiMeH₂))₄;    -   the precursor being W(═O)(NHiPr)₂(N(SiMe₃)₂)₂;    -   the precursor being W(═O)(NiPr₂)₂(N(SiMe₃)₂)₂;    -   the precursor having the formula M(═O)₂(NR₂)₂;    -   the precursor being Mo(═O)₂(NMe₂)₂;    -   the precursor being Mo(═O)₂(NMeEt)₂;    -   the precursor being Mo(═O)₂(NEt₂)₂;    -   the precursor being Mo(═O)₂(NiPr₂)₂;    -   the precursor being Mo(═O)₂(NnPr₂)₂;    -   the precursor being Mo(═O)₂(NiBu₂)₂;    -   the precursor being Mo(═O)₂(NnBu₂)₂;    -   the precursor being Mo(═O)₂(NtBu₂)₂;    -   the precursor being Mo(═O)₂(NsBu₂)₂;    -   the precursor being Mo(═O)₂(NtAm₂)₂;    -   the precursor being Mo(═O)₂(NMe₂)(NtBu₂);    -   the precursor being Mo(═O)₂(NiPr₂)(NtBu₂);    -   the precursor being Mo(═O)₂(N(SiMe₃)₂)₂;    -   the precursor being Mo(═O)₂(N(SiHMe₂)₂)₂;    -   the precursor being Mo(═O)₂(N(SiMeH₂)₂)₂;    -   the precursor being Mo(═O)₂(NHMe)₂;    -   the precursor being Mo(═O)₂(NHEt)₂;    -   the precursor being Mo(═O)₂(NHiPr)₂;    -   the precursor being Mo(═O)₂(NHnPr)₂;    -   the precursor being Mo(═O)₂(NHiBu)₂;    -   the precursor being Mo(═O)₂(NHnBu)₂;    -   the precursor being Mo(═O)₂(NHtBu)₂;    -   the precursor being Mo(═O)₂(NHsBu)₂;    -   the precursor being Mo(═O)₂(NHtAm)₂;    -   the precursor being Mo(═O)₂(NHMe)(NtBu₂);    -   the precursor being Mo(═O)₂(NiPr₂)(NHtBu);    -   the precursor being Mo(═O)₂(NHSiMe₃)₂;    -   the precursor being Mo(═O)₂(NH(SiHMe₂))₂;    -   the precursor being Mo(═O)₂(NH(SiMeH₂))₂;    -   the precursor being Mo(═O)₂(NHiPr)(N(SiMe₃)₂);    -   the precursor being Mo(═O)₂(NiPr₂)(N(SiMe₃)₂);    -   the precursor being W(═O)₂(NMe₂)₂;    -   the precursor being W(═O)₂(NMeEt)₂;    -   the precursor being W(═O)₂(NEt₂)₂;    -   the precursor being W(═O)₂(NiPr₂)₂;    -   the precursor being W(═O)₂(NnPr₂)₂;    -   the precursor being W(═O)₂(NiBu₂)₂;    -   the precursor being W(═O)₂(NnBu₂)₂;    -   the precursor being W(═O)₂(NtBu₂)₂;    -   the precursor being W(═O)₂(NsBu₂)₂;    -   the precursor being W(═O)₂(NtAm₂)₂;    -   the precursor being W(═O)₂(NMe₂)(NtBu₂);    -   the precursor being W(═O)₂(NiPr₂)(NtBu₂);    -   the precursor being W(═O)₂(N(SiMe₃)₂)₂;    -   the precursor being W(═O)₂(N(SiHMe₂)₂)₂;    -   the precursor being W(═O)₂(N(SiMeH₂)₂)₂;    -   the precursor being W(═O)₂(NHMe)₂;    -   the precursor being W(═O)₂(NHEt)₂;    -   the precursor being W(═O)₂(NHiPr)₂;    -   the precursor being W(═O)₂(NHnPr)₂;    -   the precursor being W(═O)₂(NHiBu)₂;    -   the precursor being W(═O)₂(NHnBu)₂;    -   the precursor being W(═O)₂(NHtBu)₂;    -   the precursor being W(═O)₂(NHsBu)₂;    -   the precursor being W(═O)₂(NHtAm)₂;    -   the precursor being W(═O)₂(NHMe)(NtBu₂);    -   the precursor being W(═O)₂(NiPr₂)(NHtBu);    -   the precursor being W(═O)₂(NHSiMe₃)₂;    -   the precursor being W(═O)₂(NH(SiHMe₂))₂;    -   the precursor being W(═O)₂(NH(SiMeH₂))₂;    -   the precursor being W(═O)₂(NHiPr)(N(SiMe₃)₂);    -   the precursor being W(═O)₂(NiPr₂)(N(SiMe₃)₂);    -   the precursor having the formula M(═NR)₂(OR)₂;    -   the precursor being Mo(═NMe)₂(OMe)₂;    -   the precursor being Mo(═NEt)₂(OEt)₂;    -   the precursor being Mo(═NiPr)₂(OiPr)₂;    -   the precursor being Mo(═NnPr)₂(OnPr)₂;    -   the precursor being Mo(═NiBu)₂(OiBu)₂;    -   the precursor being Mo(═NsBu)₂(OsBu)₂;    -   the precursor being Mo(═NtBu)₂(OtBu)₂;    -   the precursor being Mo(═NnBu)₂(OnBu)₂;    -   the precursor being Mo(═NtAm)₂(OtAm)₂;    -   the precursor being Mo(═NSiMe₃)₂(OSiMe₃)₂;    -   the precursor being Mo(═NSiHMe₂)₂(OSiHMe₂)₂;    -   the precursor being Mo(═NSiH₂Me)₂(OSiH₂Me)₂;    -   the precursor being Mo(═NMe)₂(OtBu)₂;    -   the precursor being Mo(═NEt)₂(OiPr)₂;    -   the precursor being Mo(═NiPr)₂(OMe)₂;    -   the precursor being Mo(═NiPr)₂(OEt)₂;    -   the precursor being Mo(═NiPr)₂(OtBu)₂;    -   the precursor being Mo(═NiPr)₂(OsBu)₂;    -   the precursor being Mo(═NiPr)₂(OiBu)₂;    -   the precursor being Mo(═NiPr)₂(OnBu)₂;    -   the precursor being Mo(═NiPr)₂(OtAmyl)₂;    -   the precursor being Mo(═NiPr)₂(OSiMe₃)₂;    -   the precursor being Mo(═NtBu)₂(OMe)₂;    -   the precursor being Mo(═NtBu)₂(OEt)₂;    -   the precursor being Mo(═NtBu)₂(OiPr)₂;    -   the precursor being Mo(═NtBu)₂(OsBu)₂;    -   the precursor being Mo(═NtBu)₂(OiBu)₂;    -   the precursor being Mo(═NtBu)₂(OnBu)₂;    -   the precursor being Mo(═NtBu)₂(OtAmyl)₂;    -   the precursor being Mo(═NtAm)₂(OMe)₂;    -   the precursor being Mo(═NtAm)₂(OEt)₂;    -   the precursor being Mo(═NtAm)₂(OiPr)₂;    -   the precursor being Mo(═NtAm)₂(OtBu)₂;    -   the precursor being Mo(═NtAm)₂(OsBu)₂;    -   the precursor being Mo(═NtAm)₂(OiBu)₂;    -   the precursor being Mo(═NtAm)₂(OnBu)₂;    -   the precursor being Mo(═NSiMe₃)₂(OMe)(OEt);    -   the precursor being Mo(═NSiHMe₂)₂(OMe)(OEt);    -   the precursor being Mo(═NSiH₂Me)₂(OMe)(OEt);    -   the precursor being Mo(═NSiMe₃)(═NtBu)(OMe)₂;    -   the precursor being Mo(═NSiMe₃)(═NtBu)(OEt)₂;    -   the precursor being Mo(═NSiMe₃)(═NiPr)(OMe)₂;    -   the precursor being Mo(═NSiMe₃)(═NiPr)(OEt)₂;    -   the precursor being W(═NMe)₂(OMe)₂;    -   the precursor being W(═NEt)₂(OEt)₂;    -   the precursor being W(═NiPr)₂(OiPr)₂;    -   the precursor being W(═NnPr)₂(OnPr)₂;    -   the precursor being W(═NiBu)₂(OiBu)₂;    -   the precursor being W(═NsBu)₂(OsBu)₂;    -   the precursor being W(═NtBu)₂(OtBu)₂;    -   the precursor being W(═NnBu)₂(OnBu)₂;    -   the precursor being W(═NtAm)₂(OtAm)₂;    -   the precursor being W(═NSiMe₃)₂(OSiMe₃)₂;    -   the precursor being W(═NSiHMe₂)₂(OSiHMe₂)₂;    -   the precursor being W(═NSiH₂Me)₂(OSiH₂Me)₂;    -   the precursor being W(═NMe)₂(OtBu)₂;    -   the precursor being W(═NEt)₂(OiPr)₂;    -   the precursor being W(═NiPr)₂(OMe)₂;    -   the precursor being W(═NiPr)₂(OEt)₂;    -   the precursor being W(═NtBu)₂(OMe)₂;    -   the precursor being W(═NtBu)₂(OEt)₂;    -   the precursor being W(═NtAm)₂(OMe)₂;    -   the precursor being W(═NtAm)₂(OEt)₂;    -   the precursor being W(═NSiMe₃)₂(OMe)(OEt);    -   the precursor being W(═NSiHMe₂)₂(OMe)(OEt);    -   the precursor being W(═NSiH₂Me)₂(OMe)(OEt);    -   the precursor being W(═NSiMe₃)(═NtBu)(OMe)₂;    -   the precursor being W(═NSiMe₃)(═NtBu)(OEt)₂;    -   the precursor being W(═NSiMe₃)(═NiPr)(OMe)₂;    -   the precursor being W(═NSiMe₃)(═NiPr)(OEt)₂;    -   the precursor having the formula M(═O)(OR)₄;    -   each R independently being selected from H, Me, Et, nPr, iPr,        tBu, sBu, iBu, nBu, tAmyl, SiMe₃, SiMe₂H, or SiH₂Me;    -   each R independently being iPr or tBu;    -   the precursor being Mo(═O)(OMe)₄;    -   the precursor being Mo(═O)(OEt)₄;    -   the precursor being Mo(═O)(OiPr)₄;    -   the precursor being Mo(═O)(OnPr)₄;    -   the precursor being Mo(═O)(OiBu)₄;    -   the precursor being Mo(═O)(OnBu)₄;    -   the precursor being Mo(═O)(OtBu)₄;    -   the precursor being Mo(═O)(OsBu)₄;    -   the precursor being Mo(═O)(OtAm)₄;    -   the precursor being Mo(═O)(OMe)₂(OtBu)₂;    -   the precursor being Mo(═O)(OiPr)₂(OtBu)₂;    -   the precursor being Mo(═O)(OSiMe₃)₄;    -   the precursor being Mo(═O)(OSiHMe₂)₄;    -   the precursor being Mo(═O)(OSiMeH₂)₄;    -   the precursor being Mo(═O)(OiPr)₂(OSiMe₃)₂;    -   the precursor being W(═O)(OMe)₄;    -   the precursor being W(═O)(OnPr)₄;    -   the precursor being W(═O)(OiBu)₄;    -   the precursor being W(═O)(OnBu)₄;    -   the precursor being W(═O)(OsBu)₄;    -   the precursor being W(═O)(OtAm)₄;    -   the precursor being W(═O)(OMe)₂(OtBu)₂;    -   the precursor being W(═O)(OiPr)₂(OtBu)₂;    -   the precursor being W(═O)(OSiMe₃)₄;    -   the precursor being W(═O)(OSiHMe₂)₄;    -   the precursor being W(═O)(OSiMeH₂)₄;    -   the precursor being W(═O)(OiPr)₂(OSiMe₃)₂;    -   the precursor having the formula M(═O)₂(OR)₂;    -   each R independently being selected from H, Me, Et, nPr, iPr,        tBu, sBu, iBu, nBu, tAmyl, SiMe₃, SiMe₂H, or SiH₂Me;    -   each R independently being iPr or tBu;    -   the precursor being Mo(═O)₂(OMe)₂;    -   the precursor being Mo(═O)₂(OEt)₂;    -   the precursor being Mo(═O)₂(OiPr)₂;    -   the precursor being Mo(═O)₂(OnPr)₂;    -   the precursor being Mo(═O)₂(OiBu)₂;    -   the precursor being Mo(═O)₂(OnBu)₂;    -   the precursor being Mo(═O)₂(OtBu)₂;    -   the precursor being Mo(═O)₂(OsBu)₂;    -   the precursor being Mo(═O)₂(OtAm)₂;    -   the precursor being Mo(═O)₂(OMe)(OtBu);    -   the precursor being Mo(═O)₂(OiPr)(OtBu);    -   the precursor being Mo(═O)₂(OSiMe₃)₂;    -   the precursor being Mo(═O)₂(OSiHMe₂)₂;    -   the precursor being Mo(═O)₂(OSiMeH₂)₂;    -   the precursor being Mo(═O)₂(OiPr)(OSiMe₃);    -   the precursor being W(═O)₂(OMe)₂;    -   the precursor being W(═O)₂(OEt)₂;    -   the precursor being W(═O)₂(OnPr)₂;    -   the precursor being W(═O)₂(OiPr)₂;    -   the precursor being W(═O)₂(OiBu)₂;    -   the precursor being W(═O)₂(OnBu)₂;    -   the precursor being W(═O)₂(OsBu)₂;    -   the precursor being W(═O)₂(OtBu)₂;    -   the precursor being W(═O)₂(OtAm)₂;    -   the precursor being W(═O)₂(OMe)(OtBu);    -   the precursor being W(═O)₂(OiPr)(OtBu);    -   the precursor being W(═O)₂(OSiMe₃)₂;    -   the precursor being W(═O)₂(OSiHMe₂)₂;    -   the precursor being W(═O)₂(OSiMeH₂)₂;    -   the precursor being W(═O)₂(OiPr)(OSiMe₃);    -   the composition comprising between approximately 95% w/w and        approximately 100% w/w of the precursor;    -   the composition comprising between approximately 98% w/w and        approximately 100% w/w of the precursor;    -   the composition comprising between approximately 99% w/w and        approximately 100% w/w of the precursor;    -   the composition comprising between approximately 0.1% w/w and        approximately 50% w/w of the precursor;    -   the composition comprising between approximately 0 atomic % and        5 atomic % of M(OR)₆;    -   the composition comprising between approximately 0 atomic % and        5 atomic % of M(═NR)₂Cl(OR);    -   the composition comprising between approximately 0 ppmw and 200        ppm of Cl;    -   further comprising a solvent.    -   the solvent being selected from the group consisting of C1-C16        hydrocarbons, THF, DMO, ether, pyridine, and combinations        thereof;    -   the solvent being a C1-C16 hydrocarbons;    -   the solvent being tetrahydrofuran (THF);    -   the solvent being dimethyl oxalate (DMO);    -   the solvent being ether;    -   the solvent being pyridine;    -   the solvent being ethanol; and    -   the solvent being isopropanol.

Also disclosed are processes for the deposition of Group 6 transitionmetal-containing films on substrates. The Group 6 film formingcompositions disclosed above is introduced into a reactor having asubstrate disposed therein. At least part of the Group 6 transitionmetal-containing precursor is deposited onto the substrate to form theGroup 6 transition metal-containing film. The disclosed processes mayfurther include one or more of the following aspects:

-   -   introducing at least one reactant into the reactor;    -   the reactant being plasma-treated;    -   the reactant being remote plasma-treated;    -   the reactant not being plasma-treated;    -   the reactant being selected from the group consisting of H₂,        H₂CO, N₂H₄, NH₃, SiH₄, Si₂H₆, Si₃H₈, SiH₂Me₂, SiH₂Et₂, N(SiH₃)₃,        hydrogen radicals thereof, and mixtures thereof;    -   the reactant being H₂;    -   the reactant being NH₃;    -   the reactant being selected from the group consisting of: O₂,        O₃, H₂O, H₂O₂, NO, N₂O, NO₂, oxygen radicals thereof, and        mixtures thereof;    -   the reactant being H₂O;    -   the reactant being plasma treated O₂;    -   the reactant being O₃;    -   the Group 6 film forming composition and the reactant being        introduced into the reactor simultaneously;    -   the reactor being configured for chemical vapor deposition;    -   the reactor being configured for plasma enhanced chemical vapor        deposition;    -   the Group 6 film forming composition and the reactant being        introduced into the chamber sequentially;    -   the reactor being configured for atomic layer deposition;    -   the reactor being configured for plasma enhanced atomic layer        deposition;    -   the reactor being configured for spatial atomic layer        deposition;    -   the Group 6 transition metal-containing film being a pure Group        6 transition metal thin film;    -   the Group 6 transition metal-containing film being a Group 6        transition metal silicide (MkSiI, wherein M is the Group 6        transition metal and each of k and l is an integer which        inclusively range from 1 to 6);    -   the Group 6 transition metal-containing film being a Group 6        transition metal oxide (MnOm, wherein M is the Group 6        transition metal and each of n and m is an integer which        inclusively range from 1 to 6);    -   the Group 6 transition metal-containing film being MoO₂, MoO₃,        W₂O₃, WO₂, WO₃, or W₂O₅;    -   the Group 6 transition metal-containing film being a Group 6        transition metal nitride (M_(o)N_(p), wherein M is the Group 6        transition metal and each of o and p is an integer which        inclusively range from 1 to 6); and    -   the Group 6 transition metal-containing film being Mo₂N, MoN,        MoN₂, W₂N, WN, or WN₂.

BRIEF DESCRIPTION OF THE DRAWINGS

For a further understanding of the nature and objects of the presentinvention, reference should be made to the following detaileddescription, taken in conjunction with the accompanying drawings, inwhich like elements are given the same or analogous reference numbersand wherein:

FIG. 1 is a block diagram that schematically illustrates an exemplaryALD apparatus;

FIG. 2 is a ThermoGravimetric Analysis (TGA) graph demonstrating thepercentage of weight loss with increasing temperature ofMo(═NtBu)₂(OtBu)₂, Mo(═NtBu)₂(OiPr)₂, Mo(═NtBu)₂(OEt)₂,Mo(═NtBu)₂(OiPr)(NMe₂), and Mo(═NtBu)₂(NMe₂)₂; and

FIG. 3 is a TGA graph demonstrating the percentage of weight loss withincreasing temperature of Mo(═NtBu)₂(OtBu)₂ before and after undergoing100° C. stability testing.

DESCRIPTION OF PREFERRED EMBODIMENTS

Disclosed are Group 6 film forming compositions comprising Group 6transition metal-containing precursors selected from the groupconsisting of:M(═O)(NR₂)₄  Formula I,M(═O)₂(NR₂)₂  Formula II,M(═NR)₂(OR)₂  Formula III,M(═O)(OR)₄  Formula IV, andM(═O)₂(OR)₂  Formula V,wherein M is Mo or W and each R is independently H, a C1 to C6 alkylgroup, or SiR′₃, wherein R′ is H or a C1 to C6 alkyl group.

The Group 6 transition metal-containing precursor may have Formula I,M(═O)(NR₂)₄, wherein M is Mo or W and each R is independently H, a C1 toC6 alkyl group, or SiR′₃, wherein R′ is H or a C1 to C6 alkyl group.Preferably, each R is independently H, Me, Et, iPr, or tBu.

Exemplary molybdenum precursors of Formula I include Mo(═O)(NMe₂)₄,Mo(═O)(NMeEt)₄, Mo(═O)(NEt₂)₄, Mo(═O)(NiPr₂)₄, Mo(═O)(NnPr₂)₄,Mo(═O)(NiBu₂)₄, Mo(═O)(NnBu₂)₄, Mo(═O)(NtBu₂)₄, Mo(═O)(NsBu₂)₄,Mo(═O)(NtAm₂)₄, Mo(═O)(NMe₂)₂(NtBu₂)₂, Mo(═O)(NiPr₂)₂(NtBu₂)₂,Mo(═O)(N(SiMe₃)₂)₄, Mo(═O)(N(SiHMe₂)₂)₄, Mo(═O)(N(SiMeH₂)₂)₄,Mo(═O)(NHMe)₄, Mo(═O)(NHEt)₄, Mo(═O)(NHiPr)₄, Mo(═O)(NHnPr)₄,Mo(═O)(NHiBu)₄, Mo(═O)(NHnBu)₄, Mo(═O)(NHtBu)₄, Mo(═O)(NHsBu)₄,Mo(═O)(NHtAm)₄, Mo(═O)(NHMe)₂(NtBu₂)₂, Mo(═O)(NiPr₂)₂(NHtBu)₂,Mo(═O)(NHSiMe₃)₄, Mo(═O)(NH(SiHMe₂))₄, Mo(═O)(NH(SiMeH₂))₄,Mo(═O)(NHiPr)₂(N(SiMe₃)₂)₂, and Mo(═O)(NiPr₂)₂(N(SiMe₃)₂)₂.

Exemplary tungsten precursors of Formula I include W(═O)(NMe₂)₄,W(═O)(NMeEt)₄, W(═O)(NEt₂)₄, W(═O)(NiPr₂)₄, W(═O)(NnPr₂)₄,W(═O)(NiBu₂)₄, W(═O)(NnBu₂)₄, W(═O)(NtBu₂)₄, W(═O)(NsBu₂)₄,W(═O)(NtAm₂)₄, W(═O)(NMe₂)₂(NtBu₂)₂, W(═O)(NiPr₂)₂(NtBu₂)₂,W(═O)(N(SiMe₃)₂)₄, W(═O)(N(SiHMe₂)₂)₄, W(═O)(N(SiMeH₂)₂)₄, W(═O)(NHMe)₄,W(═O)(NHEt)₄, W(═O)(NHiPr)₄, W(═O)(NHnPr)₄, W(═O)(NHiBu)₄,W(═O)(NHnBu)₄, W(═O)(NHtBu)₄, W(═O)(NHsBu)₄, W(═O)(NHtAm)₄,W(═O)(NHMe)₂(NtBu₂)₂, W(═O)(NiPr₂)₂(NHtBu)₂, W(═O)(NHSiMe₃)₄,W(═O)(NH(SiHMe₂))₄, W(═O)(NH(SiMeH₂))₄, W(═O)(NHiPr)₂(N(SiMe₃)₂)₂, andW(═O)(NiPr₂)₂(N(SiMe₃)₂)₂.

The precursors of Formula I may be synthesized as described in InorganicChemistry, Vol. 26, No. 18, 1987. More particularly, M(═O)Cl₄ may bereacted with 1 equivalent of MeOH followed by 4 equivalents of the Li orNa salt of the corresponding amine (LiNR₂ or NaNR₂) to produceM(═O)(NR₂)₄.

The Group 6 transition metal-containing precursor may have Formula II,M(═O)₂(NR₂)₂, wherein M is Mo or W and each R is independently H, a C1to C6 alkyl group, or SiR′₃, wherein R′ is H or a C1 to C6 alkyl group.Preferably, each R is independently H, Me, Et, iPr, or tBu.

Exemplary molybdenum precursors of Formula II include Mo(═O)₂(NMe₂)₂,Mo(═O)₂(NMeEt)₂, Mo(═O)₂(NEt₂)₂, Mo(═O)₂(NiPr₂)₂, Mo(═O)₂(NnPr₂)₂,Mo(═O)₂(NBu₂)₂, Mo(═O)₂(NnBu₂)₂, Mo(═O)₂(NtBu₂)₂, Mo(═O)₂(NsBu₂)₂,Mo(═O)₂(NtAm₂)₂, Mo(═O)₂(NMe₂)(NtBu₂), Mo(═O)₂(NiPr₂)(NtBu₂),Mo(═O)₂(N(SiMe₃)₂)₂, Mo(═O)₂(N(SiHMe₂)₂)₂, Mo(═O)₂(N(SiMeH₂)₂)₂,Mo(═O)₂(NHMe)₂, Mo(═O)₂(NHEt)₂, Mo(═O)₂(NHiPr)₂, Mo(═O)₂(NHnPr)₂,Mo(═O)₂(NHiBu)₂, Mo(═O)₂(NHnBu)₂, Mo(═O)₂(NHtBu)₂, Mo(═O)₂(NHsBu)₂,Mo(═O)₂(NHtAm)₂, Mo(═O)₂(NHMe)(NtBu₂), Mo(═O)₂(NiPr₂)(NHtBu),Mo(═O)₂(NHSiMe₃)₂, Mo(═O)₂(NH(SiHMe₂))₂, Mo(═O)₂(NH(SiMeH₂))₂,Mo(═O)₂(NHiPr)(N(SiMe₃)₂), and Mo(═O)₂(NiPr₂)(N(SiMe₃)₂).

Exemplary tungsten precursors of Formula II include W(═O)₂(NMe₂)₂,W(═O)₂(NMeEt)₂, W(═O)₂(NEt₂)₂, W(═O)₂(NiPr₂)₂, W(═O)₂(NnPr₂)₂,W(═O)₂(NBu₂)₂, W(═O)₂(NnBu₂)₂, W(═O)₂(NtBu₂)₂, W(═O)₂(NsBu₂)₂,W(═O)₂(NtAm₂)₂, W(═O)₂(NMe₂)(NtBu₂), W(═O)₂(NiPr₂)(NtBu₂),W(═O)₂(N(SiMe₃)₂)₂, W(═O)₂(N(SiHMe₂)₂)₂, W(═O)₂(N(SiMeH₂)₂)₂,W(═O)₂(NHMe)₂, W(═O)₂(NHEt)₂, W(═O)₂(NHiPr)₂, W(═O)₂(NHnPr)₂,W(═O)₂(NHiBu)₂, W(═O)₂(NHnBu)₂, W(═O)₂(NHtBu)₂, W(═O)₂(NHsBu)₂,W(═O)₂(NHtAm)₂, W(═O)₂(NHMe)(NtBu₂), W(═O)₂(NiPr₂)(NHtBu),W(═O)₂(NHSiMe₃)₂, W(═O)₂(NH(SiHMe₂))₂, W(═O)₂(NH(SiMeH₂))₂,W(═O)₂(NHiPr)(N(SiMe₃)₂), and W(═O)₂(NiPr₂)(N(SiMe₃)₂).

The precursors of Formula II may be synthesized by reacting M(═O)Cl₂with 1 equivalent of methanol followed by 2 equivalents of the Li or Nasalt of the corresponding amine (LiNR₂ or NaNR₂) to produceM(═O)₂(NR₂)₂.

The Group 6 transition metal-containing precursor may have Formula III,M(═NR)₂(OR)₂, wherein M is Mo or W and each R is independently H, a C1to C6 alkyl group, or SiR′₃, wherein R′ is H or a C1 to C6 alkyl group.Preferably, each R is independently H, Me, Et, iPr, tBu, or tAmyl.

Exemplary molybdenum precursors of Formula III include Mo(═NMe)₂(OMe)₂,Mo(═NEt)₂(OEt)₂, Mo(═NiPr)₂(OiPr)₂, Mo(═NnPr)₂(OnPr)₂,Mo(═NiBu)₂(OiBu)₂, Mo(═NsBu)₂(OsBu)₂, Mo(═NtBu)₂(OtBu)₂,Mo(═NnBu)₂(OnBu)₂, Mo(═NtAm)₂(OtAm)₂, Mo(═NSiMe₃)₂(OSiMe₃)₂,Mo(═NSiHMe₂)₂(OSiHMe₂)₂, Mo(═NSiH₂Me)₂(OSiH₂Me)₂, Mo(═NMe)₂(OtBu)₂,Mo(═NEt)₂(OiPr)₂, Mo(═NiPr)₂(OMe)₂, Mo(═NiPr)₂(OEt)₂, Mo(═NiPr)₂(OsBu)₂,Mo(═NiPr)₂(OnBu)₂, Mo(═NiPr)₂(OiBu)₂, Mo(═NiPr)₂(OtBu)₂,Mo(═NiPr)₂(OtAmyl)₂, Mo(═NtBu)₂(OMe)₂, Mo(═NtBu)₂(OEt)₂,Mo(═NtBu)₂(OiPr)₂, Mo(═NtBu)₂(OnBu)₂, Mo(═NtBu)₂(OiBu)₂,Mo(═NtBu)₂(OsBu)₂, Mo(═NtBu)₂(OtAmyl)₂, Mo(═NtAm)₂(OMe)₂,Mo(═NtAm)₂(OEt)₂, Mo(═NtAm)₂(OiPr)₂, Mo(═NtAm)₂(OnBu)₂,Mo(═NtAm)₂(OtBu)₂, Mo(═NtAm)₂(OiBu)₂, Mo(═NtAm)₂(OsBu)₂,Mo(═NSiMe₃)₂(OMe)(OEt), Mo(═NSiHMe₂)₂(OMe)(OEt),Mo(═NSiH₂Me)₂(OMe)(OEt), Mo(═NSiMe₃)(═NtBu)(OMe)₂,Mo(═NSiMe₃)(═NtBu)(OEt)₂, Mo(═NSiMe₃)(═NiPr)(OMe)₂, andMo(═NSiMe₃)(═NiPr)(OEt)₂.

Exemplary tungsten precursors of Formula III include W(═NMe)₂(OMe)₂,W(═NEt)₂(OEt)₂, W(═NiPr)₂(OiPr)₂, W(═NnPr)₂(OnPr)₂, W(═NiBu)₂(OiBu)₂,W(═NsBu)₂(OsBu)₂, W(═NtBu)₂(OtBu)₂, W(═NnBu)₂(OnBu)₂, W(═NtAm)₂(OtAm)₂,W(═NSiMe₃)₂(OSiMe₃)₂, W(═NSiHMe₂)₂(OSiHMe₂)₂, W(═NSiH₂Me)₂(OSiH₂Me)₂,W(═NMe)₂(OtBu)₂, W(═NEt)₂(OiPr)₂, W(═NiPr)₂(OMe)₂, W(═NiPr)₂(OEt)₂,W(═NiPr)₂(OtBu)₂, W(═NiPr)₂(OnBu)₂, W(═NiPr)₂(OiBu)₂, W(═NiPr)₂(OsBu)₂,W(═NiPr)₂(OtAmyl)₂, W(═NtBu)₂(OMe)₂, W(═NtBu)₂(OEt)₂, W(═NtBu)₂(OiPr)₂,W(═NtBu)₂(OnBu)₂, W(═NtBu)₂(OiBu)₂, W(═NtBu)₂(OsBu)₂,W(═NtBu)₂(OtAmyl)₂, W(═NtAm)₂(OMe)₂, W(═NtAm)₂(OEt)₂, W(═NtAm)₂(OiPr)₂,W(═NtAm)₂(OnBu)₂, W(═NtAm)₂(OtBu)₂, W(═NtAm)₂(OiBu)₂, W(═NtAm)₂(OsBu)₂,W(═NSiMe₃)₂(OMe)(OEt), W(═NSiHMe₂)₂(OMe)(OEt), W(═NSiH₂Me)₂(OMe)(OEt),W(═NSiMe₃)(═NtBu)(OMe)₂, W(═NSiMe₃)(═NtBu)(OEt)₂,W(═NSiMe₃)(═NiPr)(OMe)₂, and W(═NSiMe₃)(═NiPr)(OEt)₂.

The precursors of Formula III may be synthesized according to themethods disclosed in Dalton Transactions (2003) (23) 4457-4465. Moreparticularly the ethylene glycol diethyl ether adduct of M(═NR)₂X₂ maybe reacted with LiOR′ or NaOR′ to produce Mo(═NR)₂(OR′)₂, wherein X is ahalide and R and R′ are both independently R as defined above butdifferentiated to indicate where each of R and R′ are located on thefinal product.

The Group 6 transition metal-containing precursor may have Formula IV,M(═O)(OR)₄, wherein M is Mo or W and each R is independently H, a C1 toC6 alkyl group, or SiR′₃, wherein R′ is H or a C1 to C6 alkyl group.Preferably, each R is independently iPr, tBu, sBu, or tAmyl.

Exemplary molybdenum precursors of Formula IV include Mo(═O)(OMe)₄,Mo(═O)(OEt)₄, Mo(═O)(OiPr)₄, Mo(═O)(OnPr)₄, Mo(═O)(OiBu)₄,Mo(═O)(OnBu)₄, Mo(═O)(OtBu)₄, Mo(═O)(OsBu)₄, Mo(═O)(OtAm)₄,Mo(═O)(OMe)₂(OtBu)₂, Mo(═O)(OiPr)₂(OtBu)₂, Mo(═O)(OSiMe₃)₄,Mo(═O)(OSiHMe₂)₄, Mo(═O)(OSiMeH₂)₄, and Mo(═O)(OiPr)₂(OSiMe₃)₂.

Exemplary tungsten precursors of Formula IV include W(═O)(OMe)₄,W(═O)(OnPr)₄, W(═O)(OiBu)₄, W(═O)(OnBu)₄, W(═O)(OsBu)₄, W(═O)(OtAm)₄,W(═O)(OMe)₂(OtBu)₂, W(═O)(OiPr)₂(OtBu)₂, W(═O)(OSiMe₃)₄,W(═O)(OSiHMe₂)₄, W(═O)(OSiMeH₂)₄, and W(═O)(OiPr)₂(OSiMe₃)₂.

The precursors of Formula IV may be synthesized according to the methodsdisclosed in the Journal of the American Chemical Society (1981) 103(5)1305-6. More particularly M₂(OR)₆ may be reacted with 2 equivalents ofO₂ to produce Mo(═O)(OR)₄. Alternatively, the precursors of Formula IVmay be synthesized according to the methods disclosed in Organometallics1982, 1, 148-155. More particularly, M(═O)Cl₄ may be reacted with 4equivalents of Li or Na salts of the corresponding alcohol (LiOR orNaOR, wherein R is defined as above) to produce M(═O)(OR)₄.

The Group 6 transition metal-containing precursor may have Formula V,M(═O)₂(OR)₂, wherein M is Mo or W and each R is independently H, a C1 toC6 alkyl group, or SiR′₃, wherein R′ is H or a C1 to C6 alkyl group.Preferably, each R is independently tBu, sBu, iBu or tAmyl.

Exemplary molybdenum precursors of Formula V include Mo(═O)₂(OMe)₂,Mo(═O)₂(OEt)₂, Mo(═O)₂(OiPr)₂, Mo(═O)₂(OnPr)₂, Mo(═O)₂(OiBu)₂,Mo(═O)₂(OnBu)₂, Mo(═O)₂(OtBu)₂, Mo(═O)₂(OsBu)₂, Mo(═O)₂(OtAm)₂,Mo(═O)₂(OMe)(OtBu), Mo(═O)₂(OiPr)(OtBu), Mo(═O)₂(OSiMe₃)₂,Mo(═O)₂(OSiHMe₂)₂, Mo(═O)₂(OSiMeH₂)₂, and Mo(═O)₂(OtBu)(OSiMe₃).

Exemplary tungsten precursors of Formula V include W(═O)₂(OMe)₂,W(═O)₂(OEt)₂, W(═O)₂(OiPr)₂, W(═O)₂(OnPr)₂, W(═O)₂(OiBu)₂,W(═O)₂(OnBu)₂, W(═O)₂(OtBU)₂, W(═O)₂(OsBu)₂, W(═O)₂(OtAm)₂,W(═O)₂(OMe)(OtBu), W(═O)₂(OiPr)(OtBu), W(═O)₂(OSiMe₃)₂,W(═O)₂(OSiHMe₂)₂, W(═O)₂(OSiMeH₂)₂, and W(═O)₂(OtBu)(OSiMe₃).

The precursors of Formula V may be synthesized according to the methodsdisclosed in the Inorganic Chemistry (1984), 23(8), 1021-37. Moreparticularly M₂(OR)₆ may be reacted with molecular O₂ to produceM(═O)₂(OR)₂. Alternatively the precursors of Formula II may also besynthesized according to the methods disclosed in Organometallics 1982,1, 148-155. More particularly M(═O)₂Cl₂ may be reacted with 2equivalents of Lithium or Sodium salt of the corresponding alcohol(Li—OR or Na—OR) to produce Mo(═O)₂(OR)₂. In another alternative, theprecursors of Formula V may also be synthesized according to the methodsdisclosed in Inorg. Chem. 1989, 28, 1279-1283. More particularly M(═O)₃may be reacted with the corresponding tetraalkoxysilane (Si(OR)₄) toproduce Mo(═O)₂(OR)₂.

Purity of the disclosed Group 6 film forming compositions is preferablyhigher than 99.9% w/w. The disclosed Group 6 transition film formingcompositions may contain any of the following impurities: Mo(═NR)Cl(OR),wherein R is defined as above, alkylamines, dialkylamines, alkylimines,alkoxies, THF, ether, toluene, chlorinated metal compounds, lithium orsodium alkoxy, or lithium or sodium amide. Preferably, the totalquantity of these impurities is below 0.1% w/w. The purified product maybe produced by sublimation, distillation, and/or passing the gas orliquid through a suitable adsorbent, such as a 4 A molecular sieve.

The disclosed Group 6 film forming compositions may also include metalimpurities at the ppbw (part per billion weight) level. These metalimpurities include, but are not limited to, Aluminum (Al), Arsenic (As),Barium (Ba), Beryllium (Be), Bismuth (Bi), Cadmium (Cd), Calcium (Ca),Chromium (Cr), Cobalt (Co), Copper (Cu), Gallium (Ga), Germanium (Ge),Hafnium (Hf), Zirconium (Zr), Indium (In), Iron (Fe), Lead (Pb), Lithium(Li), Magnesium (Mg), Manganese (Mn), Tungsten (W), Nickel (Ni),Potassium (K), Sodium (Na), Strontium (Sr), Thorium (Th), Tin (Sn),Titanium (Ti), Uranium (U), Vanadium (V) and Zinc (Zn).

Also disclosed are methods for forming Group 6 transitionmetal-containing layers on a substrate using a vapor deposition process.The method may be useful in the manufacture of semiconductor,photovoltaic, LCD-TFT, or flat panel type devices. The disclosed Group 6film forming compositions may be used to deposit thin Group 6 transitionmetal-containing films using any vapor deposition methods known to thoseof skill in the art, such as Atomic Layer Deposition or Chemical VaporDeposition. Exemplary CVD methods include thermal CVD, plasma enhancedCVD (PECVD), pulsed CVD (PCVD), low pressure CVD (LPCVD),sub-atmospheric CVD (SACVD) or atmospheric pressure CVD (APCVD),hot-wire CVD (HWCVD, also known as cat-CVD, in which a hot wire servesas an energy source for the deposition process), radicals incorporatedCVD, and combinations thereof. Exemplary ALD methods include thermalALD, plasma enhanced ALD (PEALD), spatial isolation ALD, hot-wire ALD(HWALD), radicals incorporated ALD, and combinations thereof. Supercritical fluid deposition may also be used. The deposition method ispreferably ALD, PE-ALD, or spatial ALD in order to provide suitable stepcoverage and film thickness control.

FIG. 1 is a block diagram that schematically illustrates an example of avapor deposition apparatus that may be used to form the Group 6transition metal-containing layer. The apparatus illustrated in FIG. 1includes a reactor 11, a feed source 12 for the disclosed Group 6 filmforming compositions, a feed source 13 for reactant (typically, anoxidizing agent such as oxygen or ozone), and a feed source 14 for aninert gas that can be used as a carrier gas and/or dilution gas. Asubstrate loading and unloading mechanism (not shown) allows theinsertion and removal of deposition substrates in the reactor 11. Aheating device (not shown) is provided to reach the reactiontemperatures required for reaction of the disclosed compositions.

The Group 6 film forming composition feed source 12 may use a bubblermethod to introduce the composition into the reactor 11, and isconnected to the inert gas feed source 14 by the line L1. The line L1 isprovided with a shutoff valve V1 and a flow rate controller, forexample, a mass flow controller MFC1, downstream from this valve. Thecomposition is introduced from its feed source 12 through the line L2into the reactor 11. The following are provided on the upstream side: apressure gauge PG1, a shutoff valve V2, and a shutoff valve V3.

The reactant feed source 13 comprises a vessel that holds the reactantin gaseous, liquid, or solid form. Vapors of the reactant are introducedfrom its feed source 13 through the line L3 into the reactor 11. Ashutoff valve V4 is provided in the line L3. This line L3 is connectedto the line L2.

The inert gas feed source 14 comprises a vessel that holds inert gas ingaseous form. The inert gas can be introduced from its feed sourcethrough the line L4 into the reactor 11. Line L4 is provided with thefollowing on the upstream side: a shutoff valve V6, a mass flowcontroller MFC3, and a pressure gauge PG2. The line L4 joins with theline L3 upstream from the shutoff valve V4.

The line L5 branches off upstream from the shutoff valve V1 in the lineL1; this line L5 joins the line L2 between the shutoff valve V2 and theshutoff valve V3.

The line L5 is provided with a shutoff valve V7 and a mass flowcontroller MFC4 considered from the upstream side.

The line L6 branches off between the shutoff valves V3 and V4 into thereaction chamber 11. This line L6 is provided with a shutoff valve V8.

A line L7 that reaches to the pump PMP is provided at the bottom of thereactor 11. This line L7 contains the following on the upstream side: apressure gauge PG3, a butterfly valve BV for controlling thebackpressure, and a cold trap 15. This cold trap 15 comprises a tube(not shown) that is provided with a cooler (not shown) over itscircumference and is aimed at collecting the tungsten precursor and therelated by-products.

The reactor may be any enclosure or chamber within a device in whichdeposition methods take place such as without limitation, aparallel-plate type reactor, a cold-wall type reactor, a hot-wall typereactor, a single-wafer reactor, a multi-wafer reactor, or other typesof deposition systems under conditions suitable to cause the compoundsto react and form the layers.

The reactor contains one or multiple substrates onto which the filmswill be deposited. A substrate is generally defined as the material onwhich a process is conducted. The substrates may be any suitablesubstrate used in semiconductor, photovoltaic, flat panel, or LCD-TFTdevice manufacturing. Examples of suitable substrates include wafers,such as silicon, silica, glass, or GaAs wafers. The wafer may have oneor more layers of differing materials deposited on it from a previousmanufacturing step. For example, the wafers may include silicon layers(crystalline, amorphous, porous, etc.), silicon oxide layers, siliconnitride layers, silicon oxy nitride layers, carbon doped silicon oxide(SiCOH) layers, or combinations thereof. Additionally, the wafers mayinclude copper layers or noble metal layers (e.g. platinum, palladium,rhodium, or gold). The wafers may include barrier layers, such asmanganese, manganese oxide, etc. Plastic layers, such aspoly(3,4-ethylenedioxythiophene)poly (styrenesulfonate) [PEDOT:PSS] mayalso be used. The layers may be planar or patterned. The disclosedprocesses may deposit the Group 6-containing layer directly on the waferor directly on one or more than one (when patterned layers form thesubstrate) of the layers on top of the wafer. Furthermore, one ofordinary skill in the art will recognize that the terms “film” or“layer” used herein refer to a thickness of some material laid on orspread over a surface and that the surface may be a trench or a line.Throughout the specification and claims, the wafer and any associatedlayers thereon are referred to as substrates. For example, a molybdenumoxide film may be deposited onto a TiN layer. In subsequent processing,a zirconium oxide layer may be deposited on the molybdenum layer, asecond molybdenum layer may be deposited on the zirconium oxide layer,and a TiN layer may be deposited on the second molybdenum layer, forminga TiN/MoO_(x)/ZrO₂/MoO_(x)/TiN stack, with x ranging from 2-3inclusively, used in DRAM capacitors.

The temperature and the pressure within the reactor are held atconditions suitable for vapor depositions. In other words, afterintroduction of the vaporized composition into the chamber, conditionswithin the chamber are such that at least part of the vaporizedprecursor is deposited onto the substrate to form a Group 6 transitionmetal-containing film. For instance, the pressure in the reactor may beheld between about 1 Pa and about 10⁵ Pa, more preferably between about25 Pa and about 10³ Pa, as required per the deposition parameters.Likewise, the temperature in the reactor may be held between about 100°C. and about 500° C., preferably between about 150° C. and about 400° C.One of ordinary skill in the art will recognize that “at least part ofthe vaporized precursor is deposited” means that some or all of theprecursor reacts with or adheres to the substrate.

The temperature of the reactor may be controlled by either controllingthe temperature of the substrate holder or controlling the temperatureof the reactor wall. Devices used to heat the substrate are known in theart. The reactor wall is heated to a sufficient temperature to obtainthe desired film at a sufficient growth rate and with desired physicalstate and composition. A non-limiting exemplary temperature range towhich the reactor wall may be heated includes from approximately 100° C.to approximately 500° C. When a plasma deposition process is utilized,the deposition temperature may range from approximately 150° C. toapproximately 400° C. Alternatively, when a thermal process isperformed, the deposition temperature may range from approximately 200°C. to approximately 500° C.

The disclosed Group 6 film forming compositions may be supplied eitherin neat form or in a blend with a suitable solvent, such as ethylbenzene, xylene, mesitylene, decane, dodecane. The disclosedcompositions may be present in varying concentrations in the solvent.

The neat or blended Group 6 film forming compositions are introducedinto a reactor in vapor form by conventional means, such as tubingand/or flow meters. The compound in vapor form may be produced byvaporizing the neat or blended compound solution through a conventionalvaporization step such as direct vaporization, distillation, or bybubbling, or by using a sublimator such as the one disclosed in PCTPublication WO2009/087609 to Xu et al. The neat or blended compositionmay be fed in liquid state to a vaporizer where it is vaporized beforeit is introduced into the reactor. Alternatively, the neat or blendedcomposition may be vaporized by passing a carrier gas into a containercontaining the composition or by bubbling the carrier gas into thecomposition. The carrier gas may include, but is not limited to, Ar, He,N₂, and mixtures thereof. Bubbling with a carrier gas may also removeany dissolved oxygen present in the neat or blended composition. Thecarrier gas and composition are then introduced into the reactor as avapor.

If necessary, the container of disclosed compositions may be heated to atemperature that permits the composition to be in its liquid phase andto have a sufficient vapor pressure. The container may be maintained attemperatures in the range of, for example, approximately 0° C. toapproximately 150° C. Those skilled in the art recognize that thetemperature of the container may be adjusted in a known manner tocontrol the amount of composition vaporized.

In addition to the disclosed compositions, a reactant may also beintroduced into the reactor. The reactant may be an oxidizing gas suchas one of O₂, O₃, H₂O, H₂O₂, NO, N₂O, NO₂, oxygen containing radicalssuch as O. or OH., NO, NO₂, carboxylic acids, formic acid, acetic acid,propionic acid, and mixtures thereof. Preferably, the oxidizing gas isselected from the group consisting of O₂, O₃, H₂O, H₂O₂, oxygencontaining radicals thereof such as O. or OH., and mixtures thereof.

Alternatively, the reactant may be a reducing gas such as one of H₂,H₂CO, NH₃, SiH₄, Si₂H₆, Si₃H₈, (CH₃)₂SiH₂, (C₂H₅)₂SiH₂, (CH₃)SiH₃,(C₂H₅)SiH₃, phenyl silane, N₂H₄, N(SiH₃)₃, N(CH₃)H₂, N(C₂H₅)H₂,N(CH₃)₂H, N(C₂H₅)₂H, N(CH₃)₃, N(C₂H₅)₃, (SiMe₃)₂NH, (CH₃)HNNH₂,(CH₃)₂NNH₂, phenyl hydrazine, N-containing molecules, B₂H₆,9-borabicyclo[3,3,1]nonane, dihydrobenzenfuran, pyrazoline,trimethylaluminium, dimethylzinc, diethylzinc, radical species thereof,and mixtures thereof. Preferably, the reducing as is H₂, NH₃, SiH₄,Si₂H₆, Si₃H₈, SiH₂Me₂, SiH₂Et₂, N(SiH₃)₃, hydrogen radicals thereof, ormixtures thereof.

The reactant may be treated by a plasma, in order to decompose thereactant into its radical form. N₂ may also be utilized as a reducinggas when treated with plasma. For instance, the plasma may be generatedwith a power ranging from about 50 W to about 500 W, preferably fromabout 100 W to about 400 W. The plasma may be generated or presentwithin the reactor itself. Alternatively, the plasma may generally be ata location removed from the reactor, for instance, in a remotely locatedplasma system. One of skill in the art will recognize methods andapparatus suitable for such plasma treatment.

For example, the reactant may be introduced into a direct plasmareactor, which generates plasma in the reaction chamber, to produce theplasma-treated reactant in the reaction chamber. Exemplary direct plasmareactors include the Titan™ PECVD System produced by Trion Technologies.The reactant may be introduced and held in the reaction chamber prior toplasma processing. Alternatively, the plasma processing may occursimultaneously with the introduction of the reactant. In-situ plasma istypically a 13.56 MHz RF inductively coupled plasma that is generatedbetween the showerhead and the substrate holder. The substrate or theshowerhead may be the powered electrode depending on whether positiveion impact occurs. Typical applied powers in in-situ plasma generatorsare from approximately 30 W to approximately 1000 W. Preferably, powersfrom approximately 30 W to approximately 600 W are used in the disclosedmethods. More preferably, the powers range from approximately 100 W toapproximately 500 W. The disassociation of the reactant using in-situplasma is typically less than achieved using a remote plasma source forthe same power input and is therefore not as efficient in reactantdisassociation as a remote plasma system, which may be beneficial forthe deposition of Group 6 transition metal-containing films onsubstrates easily damaged by plasma.

Alternatively, the plasma-treated reactant may be produced outside ofthe reaction chamber. The MKS Instruments' ASTRONi® reactive gasgenerator may be used to treat the reactant prior to passage into thereaction chamber. Operated at 2.45 GHz, 7 kW plasma power, and apressure ranging from approximately 0.5 Torr to approximately 10 Torr,the reactant O₂ may be decomposed into two O. radicals. Preferably, theremote plasma may be generated with a power ranging from about 1 kW toabout 10 kW, more preferably from about 2.5 kW to about 7.5 kW.

The vapor deposition conditions within the chamber allow the disclosedcomposition and the reactant to react and form a Group 6 transitionmetal-containing film on the substrate. In some embodiments, Applicantsbelieve that plasma-treating the reactant may provide the reactant withthe energy needed to react with the disclosed precursors.

Depending on what type of film is desired to be deposited, an additionalprecursor may be introduced into the reactor. The precursor may be usedto provide additional elements to the Group 6 transitionmetal-containing film. The additional elements may include lanthanides(Ytterbium, Erbium, Dysprosium, Gadolinium, Praseodymium, Cerium,Lanthanum, Yttrium), zirconium, germanium, silicon, titanium, manganese,ruthenium, bismuth, lead, magnesium, aluminum, or mixtures of these.When an additional precursor compound is utilized, the resultant filmdeposited on the substrate contains the Group 6 transition metal incombination with at least one additional element.

The Group 6 thin film forming compositions and reactants may beintroduced into the reactor either simultaneously (chemical vapordeposition), sequentially (atomic layer deposition) or differentcombinations thereof. The reactor may be purged with an inert gasbetween the introduction of the composition and the introduction of thereactant. Alternatively, the reactant and the composition may be mixedtogether to form a reactant/composition mixture, and then introduced tothe reactor in mixture form. Another example is to introduce thereactant continuously and to introduce the Group 6 film formingcomposition by pulse (pulsed chemical vapor deposition).

The vaporized composition and the reactant may be pulsed sequentially orsimultaneously (e.g. pulsed CVD) into the reactor. Each pulse may lastfor a time period ranging from about 0.01 seconds to about 10 seconds,alternatively from about 0.3 seconds to about 3 seconds, alternativelyfrom about 0.5 seconds to about 2 seconds. In another embodiment, thereactant may also be pulsed into the reactor. In such embodiments, thepulse of each gas may last for a time period ranging from about 0.01seconds to about 10 seconds, alternatively from about 0.3 seconds toabout 3 seconds, alternatively from about 0.5 seconds to about 2seconds. In another alternative, the vaporized compositions andreactants may be simultaneously sprayed from a shower head under which asusceptor holding several wafers is spun (spatial ALD).

Depending on the particular process parameters, deposition may takeplace for a varying length of time. Generally, deposition may be allowedto continue as long as desired or necessary to produce a film with thenecessary properties. Typical film thicknesses may vary from severalangstroms to several hundreds of microns, depending on the specificdeposition process. The deposition process may also be performed as manytimes as necessary to obtain the desired film.

In one non-limiting exemplary CVD type process, the vapor phase of thedisclosed Group 6 film forming compositions and a reactant aresimultaneously introduced into the reactor. The two react to form theresulting Group 6 transition metal-containing thin film. When thereactant in this exemplary CVD process is treated with a plasma, theexemplary CVD process becomes an exemplary PECVD process. The reactantmay be treated with plasma prior or subsequent to introduction into thechamber.

In one non-limiting exemplary ALD type process, the vapor phase of thedisclosed Group 6 film forming composition is introduced into thereactor, where it is contacted with a suitable substrate. Excesscomposition may then be removed from the reactor by purging and/orevacuating the reactor. A desired gas (for example, H₂) is introducedinto the reactor where it reacts with the adsorbed composition in aself-limiting manner. Any excess reducing gas is removed from thereactor by purging and/or evacuating the reactor. If the desired film isa Group 6 transition metal film, this two-step process may provide thedesired film thickness or may be repeated until a film having thenecessary thickness has been obtained.

Alternatively, if the desired film contains Group 6 transition metal anda second element, the two-step process above may be followed byintroduction of the vapor of an additional precursor into the reactor.The additional precursor will be selected based on the nature of theGroup 6 transition metal film being deposited. After introduction intothe reactor, the additional precursor is contacted with the substrate.Any excess precursor is removed from the reactor by purging and/orevacuating the reactor. Once again, a desired gas may be introduced intothe reactor to react with the adsorbed precursor. Excess gas is removedfrom the reactor by purging and/or evacuating the reactor. If a desiredfilm thickness has been achieved, the process may be terminated.However, if a thicker film is desired, the entire four-step process maybe repeated. By alternating the provision of the Group 6 film formingcomposition, additional precursor, and reactant, a film of desiredcomposition and thickness can be deposited.

When the reactant in this exemplary ALD process is treated with aplasma, the exemplary ALD process becomes an exemplary PEALD process.The reactant may be treated with plasma prior or subsequent tointroduction into the chamber.

In a second non-limiting exemplary ALD type process, the vapor phase ofone of the disclosed Group 6 film forming compositions, for examplemolybdenum di-tertbutylimido di-tertbutoxide [Mo(═NtBu)₂(OtBu)₂], isintroduced into the reactor, where it is contacted with a TiN substrate.Excess composition may then be removed from the reactor by purgingand/or evacuating the reactor. A desired gas (for example, O₃) isintroduced into the reactor where it reacts with the absorbed precursorin a self-limiting manner to form a molybdenum oxide film. Any excessoxidizing gas is removed from the reactor by purging and/or evacuatingthe reactor. These two steps may be repeated until the molybdenum oxidefilm obtains a desired thickness, typically around 10 angstroms. ZrO₂may then be deposited on the MoO_(x) film, wherein x is inclusively 2-3.For example, ZrCp(NMe₂)₃ may serve as the Zr precursor. The secondnon-limiting exemplary ALD process described above usingMo(═NtBu)₂(OtBu)₂ and ozone may then be repeated on the ZrO₂ layer,followed by deposition of TiN on the MoO_(x) layer. The resultingTiN/MoO_(x)/ZrO₂/MoO_(x)/TiN stack may be used in DRAM capacitors.

The Group 6 transition metal-containing films resulting from theprocesses discussed above may include a pure Group 6 transition metal(M=Mn or W), Group 6 transition metal silicide (M_(k)Si_(l)), Group 6transition metal oxide (M_(n)O_(m)), Group 6 transition metal nitride(M_(o)N_(p)) film, Group 6 transition metal carbide (M_(q)C_(r)) film,or a Group 6 transition metal carbonitride (MCrNp) wherein k, l, m, n,o, p, q, and r are integers which inclusively range from 1 to 6. One ofordinary skill in the art will recognize that by judicial selection ofthe appropriate disclosed Group 6 film forming composition, optionalprecursors, and reactants, the desired film composition may be obtained.

Upon obtaining a desired film thickness, the film may be subject tofurther processing, such as thermal annealing, furnace-annealing, rapidthermal annealing, UV or e-beam curing, and/or plasma gas exposure.Those skilled in the art recognize the systems and methods utilized toperform these additional processing steps. For example, the Group 6transition metal-containing film may be exposed to a temperature rangingfrom approximately 200° C. and approximately 1000° C. for a time rangingfrom approximately 0.1 second to approximately 7200 seconds under aninert atmosphere, a H-containing atmosphere, a N-containing atmosphere,an O-containing atmosphere, or combinations thereof. Most preferably,the temperature is 400° C. for 3600 seconds under a H-containingatmosphere or an O-containing atmosphere. The resulting film may containfewer impurities and therefore may have an improved density resulting inimproved leakage current. The annealing step may be performed in thesame reaction chamber in which the deposition process is performed.Alternatively, the substrate may be removed from the reaction chamber,with the annealing/flash annealing process being performed in a separateapparatus. Any of the above post-treatment methods, but especiallythermal annealing, has been found effective to reduce carbon andnitrogen contamination of the Group 6 transition metal-containing film.This in turn tends to improve the resistivity of the film.

After annealing, the tungsten-containing films deposited by any of thedisclosed processes may have a bulk resistivity at room temperature ofapproximately 5.5 μohm·cm to approximately 70 μohm·cm, preferablyapproximately 5.5 μohm·cm to approximately 20 μohm·cm, and morepreferably approximately 5.5 μohm·cm to approximately 12 μohm·cm. Afterannealing, the molybdenum-containing films deposited by any of thedisclosed processes may have a bulk resistivity at room temperature ofapproximately 50 μohm·cm to approximately 1,000 μohm·cm. Roomtemperature is approximately 20° C. to approximately 28° C. depending onthe season. Bulk resistivity is also known as volume resistivity. One ofordinary skill in the art will recognize that the bulk resistivity ismeasured at room temperature on W or Mo films that are typicallyapproximately 50 nm thick. The bulk resistivity typically increases forthinner films due to changes in the electron transport mechanism. Thebulk resistivity also increases at higher temperatures.

In another alternative, the disclosed Group 6 film forming compositionsmay be used as doping or implantation agents. Part of the disclosedcomposition may be deposited on top of the film to be doped, such as anindium oxide (In₂O₃) film, vanadium dioxide (VO₂) film, a titanium oxidefilm, a copper oxide film, or a tin dioxide (SnO₂) film. The molybdenumor tungsten then diffuses into the film during an annealing step to formthe molybdenum-doped films {(Mo)In₂O₃, (Mo)VO₂, (Mo)TiO, (Mo)CuO, or(Mo)SnO₂} or tungsten-doped films {(W)In₂O₃, (W)VO₂, (W)TiO, (W)CuO, or(W)SnO₂}. See, e.g., US2008/0241575 to Lavoie et al., the doping methodof which is incorporated herein by reference in its entirety.Alternatively, high energy ion implantation using a variable energyradio frequency quadrupole implanter may be used to dope the molybdenumor tungsten of the disclosed compositions into a film. See, e.g.,Kensuke et al., JVSTA 16(2) March/April 1998, the implantation method ofwhich is incorporated herein by reference in its entirety. In anotheralternative, plasma doping, pulsed plasma doping or plasma immersion ionimplantation may be performed using the disclosed compositions. See,e.g., Felch et al., Plasma doping for the fabrication of ultra-shallowjunctions Surface Coatings Technology, 156 (1-3) 2002, pp. 229-236, thedoping method of which is incorporated herein by reference in itsentirety.

EXAMPLES

The following non-limiting examples are provided to further illustrateembodiments of the invention. However, the examples are not intended tobe all inclusive and are not intended to limit the scope of theinventions described herein.

Synthesis Example 1: Mo(═NtBu)₂(OiPr)₂

MoCl₂(═NtBu)₂ was synthesized by mixing 1 molar equivalent of Na₂MoO₄with 700 mL of dimethyl ether at 0° C. under mechanical stirring. 4molar equivalents of NEt₃ was added dropwise to the mixture for 10minutes. The addition funnel was rinsed with 100 mL of dimethyl ether,which was added to the mixture. 9 molar equivalents of SiMe₃Cl was addeddropwise to the mixture for 1 hour. The addition funnel was rinsed with100 mL of dimethyl ether, which was added to the mixture. 2 molarequivalents of tBuNH₂ was added dropwise to the mixture for 30 minutes.After one night at room temperature (approximately 23° C.), theresulting yellow suspension was heated to 70° C. for 10 hours. Thesuspension was cooled to room temperature and filtered. Solvent wasremoved under vacuum and resulting gold powder washed with pentane.

1 molar equivalent of MoCl₂(═NtBu)₂ was mixed with tetrahydrofuran (THF)at −78° C. under mechanical stirring. 2 molar equivalents of Li(OiPr) inTHF was added dropwise to the mixture. After one night at roomtemperature, the solvent was removed under vacuum. The resulting productwas rinsed with pentane and filtered. Solvent was removed under vacuumdistillation and the crude product purified by vacuum distillation. TheMo(═NtBu)₂(OiPr)₂ produced was a gold liquid. The open cupThermoGravimetric Analysis (TGA) graph is provided in FIG. 2. Vaporpressure at 1 Torr is 91° C.

Synthesis Example 2: Mo(═NtBu)₂(OtBu)₂

1 molar equivalent of MoCl₂(═NtBu)₂ was mixed with tetrahydrofuran (THF)at −78° C. under mechanical stirring. 2.8 molar equivalents of Li(OtBu)in THF was added dropwise to the mixture. After one night at roomtemperature, the solvent was removed under vacuum. The resulting productwas rinsed with 500 mL of pentane and filtered. Solvent was removedunder vacuum distillation and the crude product purified by vacuumdistillation. The Mo(═NtBu)₂(OiPr)₂ produced was a yellow oil. The opencup TGA graph is provided in FIG. 2. Vapor pressure at 1 Torr is 93° C.

¹H-NMR δ_(H): 9.00 ppm (s, 9H, N—C—(CH₃)₃), 9.28 ppm (s, 9H,O—C—(CH₃)₃).

The stability of Mo(═NtBu)₂(OtBu)₂ was tested by placing the sample in adry 100° C. heater for 7 weeks. The product became very slightly darker,but as shown in FIG. 3, there was no increase in residue via TGA.

Synthesis Example 3: Mo(═NtBu)₂(OEt)₂

1 molar equivalent of Mo(═NtBu)₂(NMe₂)₂ was mixed with tetrahydrofuran(THF) at −78° C. under mechanical stirring. 2 molar equivalents of EtOHwas added dropwise to the mixture. After one night at room temperature,the solvent was removed under vacuum and the resulting orange oilpurified by vacuum distillation. The purified Mo(═NtBu)₂(OEt)₂ producedwas a brown wax. The open cup TGA graph is provided in FIG. 2. Vaporpressure at 1 Torr is 129° C.

Synthesis Example 4: Mo(═O)₂(N(SiMe₃)₂)₂

1 molar equivalent of MoCl₂(═O)₂ was mixed with ether at −78° C. undermechanical stirring. 2 molar equivalents of Na(N(SiMe₃)₂)₂ in ether wasadded dropwise to the mixture. After one night at room temperature, theresulting product was filtered and purified by vacuum distillation. TheMo(═O)₂(N(SiMe₃)₂)₂ produced was a yellow colored liquid. The open cupTGA graph is provided in FIG. 2.

Comparative Synthesis Example: Mo(═NtBu)₂(NMe₂)₂

1 molar equivalent of MoCl₂(═NtBu)₂ was mixed with tetrahydrofuran (THF)at −78° C. under mechanical stirring. 2 molar equivalents of Li(NMe₂)₂in THF was added dropwise to the mixture. After one night at roomtemperature, the solvent was removed under vacuum. The resulting productwas rinsed with 300 mL of pentane and filtered. Solvent was removedunder vacuum distillation and the crude product purified by vacuumdistillation. The Mo(═NtBu)₂(OiPr)₂ produced was an orange liquid. Theopen cup TGA graph is provided in FIG. 2. Vapor pressure at 1 Torr is77° C.

Example 1

A typical ALD system, shown in FIG. 1, was used to perform ALDdeposition of a molybdenum oxide film. The pressure and temperature ofthe reactor were kept at 0.356 Torr and 250° C., respectively. TheMo(═NtBu)₂(OtBu)₂ source was stored in a canister maintained at 75° C.The precursor was delivered to the reactor for 1, 5, or 7 second using85 sccm of Argon carrier gas, followed by a 30 second Argon purge. 500sccm of the O₃ reactant was then delivered to the reactor for 1 secondfollowed by a 30 second Argon purge. The resulting MoO₂ film wasdeposited at a rate of approximately 0.4 Å/cycle. The resulting MoO₂film contained approximately 24% Mo, 73% O, 2% N and less than 1% C asdetermined by X-ray Photoelectron Spectroscopy (XPS). X ray diffractionof the resulting film showed Mo⁽⁺⁴⁾O₂, which is surprising because theprecursor is Mo⁽⁺⁶⁾. Mo⁽⁺⁶⁾ should not be reduced to Mo⁽⁺⁴⁾ in thepresence of the strong O₃ oxidizer. Applicants believe that some metalMo(0) may also be deposited, possibly in parasitic CVD mode, whichreacts with Mo⁽⁺⁶⁾O₃ and reduces it to Mo⁽⁺⁴⁾O₂. The MoO₂ film mayreduce work function of the film and, possibly due to the rutile phase,may lead to lower leakage current in a DRAM stack.

It will be understood that many additional changes in the details,materials, steps, and arrangement of parts, which have been hereindescribed and illustrated in order to explain the nature of theinvention, may be made by those skilled in the art within the principleand scope of the invention as expressed in the appended claims. Thus,the present invention is not intended to be limited to the specificembodiments in the examples given above and/or the attached drawings.

What is claimed is:
 1. A Mo film forming composition comprising aprecursor selected from the group consisting of:Mo(═O)₂(NR₂)₂  Formula II, andMo(═NR)₂(OR)₂  Formula III, wherein each R is independently H, a C1 toC6 alkyl group, or SiR′₃, wherein R′ is H or a C1 to C6 alkyl group andwherein a purity of the precursor in the Mo film forming composition isapproximately 99.9% or greater with less than 0.1% of followingimpurities combined: Mo(═NR)Cl(OR) wherein R is defined as above,alkylamines, dialkylamines, alkylimines, alkoxies, THF, ether, toluene,chlorinated metal compounds, lithium or sodium alkoxy, and lithium orsodium amide.
 2. The Mo film forming composition of claim 1, whereineach R is independently selected from the group consisting of H, Me, Et,nPr, iPr, nBu, iBu, sBu, tBu, tAmyl and SiMe₃.
 3. The Mo film formingcomposition of claim 1, wherein the precursor has the formulaMo(═O)₂(NR₂)₂.
 4. The Mo film forming composition of claim 2, whereinthe precursor has the formula Mo(═O)₂(NR₂)₂.
 5. The Mo film formingcomposition of claim 1, wherein the precursor has the formulaMo(═NR)₂(OR)₂.
 6. The Mo film forming composition of claim 2, whereinthe precursor has the formula Mo(═NR)₂(OR)₂.
 7. The Mo film formingcomposition of claim 6, wherein the precursor is Mo(═NtBu)₂(OtBu)₂.
 8. Amethod of depositing a Mo-containing film on a substrate, comprising thesteps of: introducing a vapor of the Mo film forming composition ofclaim 1 into a reactor having a substrate disposed therein anddepositing at least part of the precursor onto the substrate.
 9. Themethod of claim 8, further comprising introducing at least one reactantinto the reactor.
 10. The method of claim 9, wherein the reactant isselected from the group consisting of H₂, H₂CO N₂H₄, NH₃, SiH₄, Si₂H₆,Si₃H₈, SiH₂Me₂, SiH₂Et₂, N(SiH₃)₃, hydrogen radicals thereof, andmixtures thereof.
 11. The method of claim 9, wherein the reactant isselected from the group consisting of: O₂, O₃, H₂O, H₂O₂, NO, N₂O, NO₂,oxygen radicals thereof, and mixtures thereof.
 12. The method of claim9, wherein the Mo film forming composition and the reactant areintroduced into the reactor simultaneously and the reactor is configuredfor chemical vapor deposition.
 13. The method of claim 9, wherein the Mofilm forming composition and the reactant are introduced into thechamber sequentially and the reactor is configured for atomic layerdeposition.
 14. The method of claim 8, wherein each R is independentlyselected from the group consisting of H, Me, Et, nPr, iPr, nBu, iBu,sBu, tBu, tAmyl and SiMe₃.
 15. The method of claim 8, wherein theprecursor has the formula Mo(═O)₂(NR₂)₂.
 16. The method of claim 14,wherein the precursor has the formula Mo(═O)₂(NR₂)₂.
 17. The method ofclaim 8, wherein the precursor has the formula Mo(═NR)₂(OR)₂.
 18. Themethod of claim 14, wherein the precursor has the formula Mo(═NR)₂(OR)₂.19. The method of claim 18, wherein the precursor is Mo(═NtBu)₂(OtBu)₂.20. The Mo film forming composition of claim 1, wherein a metal impuritylevel in the Mo film forming compositions is 10 ppm or less by weightfor Aluminum (Al), Arsenic (As), Barium (Ba), Beryllium (Be), Bismuth(Bi), Cadmium (Cd), Calcium (Ca), Chromium (Cr), Cobalt (Co), Copper(Cu), Gallium (Ga), Germanium (Ge), Hafnium (Hf), Zirconium (Zr), Indium(In), Iron (Fe), Lead (Pb), Lithium (Li), Magnesium (Mg), Manganese(Mn), Tungsten (W), Nickel (Ni), Potassium (K), Sodium (Na), Strontium(Sr), Thorium (Th), Tin (Sn), Titanium (Ti), Uranium (U), Vanadium (V)and Zinc (Zn).